The 2 need to be quoted.
We have instructional videos on how to set up the gauges and gauge needles
https://youtu.be/JFrxzNGTgLc
You can check it out. The ad_value_s value you get needs to be converted to an angle in radians. Then you can make a background image of the meter, and this background image has an approximate range, which is the conversion range of the radian system.